AXIAL SKELETON OF THE PELECANID^E. 331 



and terminal portion of the pygostyle. This most anterior portion represents, more or 

 less completely, at its preaxial end the characters of the forty-second vertebra. 



THE PELVIS. 



The pelvis of the adult consists of fifteen or sixteen vertebrae with the ossa 

 innominata. Compared with that of StrutMo and the other Struthionidee it presents 

 many contrasts (Plate LIX. figs. 1-3). 



Preaxially viewed, the ilia form a much less steep arch (approximate dorsad at a 

 more obtuse angle) than in any of the Struthionidae (than even in Dromceus) ; and the 

 ilium, thus seen, is concave on each side. It differs from StrutMo and Ehea in that 

 the pubis and ischia respectively simply diverge ventrad. 



Postaxially viewed, it differs from the pelvis of all the Struthionidae in the wide 

 (transversely extended) and dorsally flattened postaxial ends of the ilia ; the ilia not 

 being laterally compressed and flattened against the sides of the vertebrae included 

 between their most postaxial parts. 



Laterally viewed, the acetabula are seen to be a little preaxiad of the antero-posterior 

 middle of the pelvis, measured from the preaxial end of the ilium to the postaxial end of 

 the pubis. The pelvis differs from that of all the Struthionidae in that (1) the ilium (il) 

 is less vertically expanded in front of the acetabulum, (2) that it is relatively more 

 vertically expanded behind the acetabulum, (3) that the ischium (i) is, at its distal end, 

 largely united with the ischium. Moreover the ischium extends postaxially beyond 

 the ilium more than in any of the Struthionidae, except StrutMo and Ehea, but about 

 as much as in StrutMo, though not nearly so much so as in Ehea. 



The pubis (p) extends postaxiad of the ischium much more than in any of the 

 Struthionidse, except StrutMo, which is so exceptional in its family in this respect. 

 The pubis is curved as in StrutMo, but scarcely ever approximates at its tip to its 

 fellow of the opposite side. The obturator-foramen is long and narrow, and shaped 

 much as in StrutMo, except that its anterior part is not divided off, that division being 

 here only indicated by a rudimentary intertrochanteric process of the ischium, which 

 does not nearly attain the pubis (Plate LIX. fig. 2, ps). 



In this respect Pelecanus differs from all the Struthionidae, except Apteryx and 

 Linornis. The pubis has no opposite corresponding process, or a mere rudiment of such. 



There is no ilio-pectineal process, by which Pelecanus differs from all the existing 

 Struthionidae, if not from Dinornis also. 



No process extends ventrad from the mid ventral margin of the pubis. 



The antero-posterior diameter of the pelvis is rather more than twice its dorso- ventral 

 dimension. 



There is an oval sacro-sciatic foramen. There is no such foramen in any of the 

 Struthionidse, except in Ehea and sometimes in Casuanus. 



VOL. x. PART vii. No. 3. August ls, 3878. 2z 



